Breaking the “Kei Car” Mold – Top Speed Tuned AZ-1: Increased displacement and NOS allows for well over 200km/h

Published : 2021/01/18 19:26 Modified : 2021/01/18 19:26

A no compromise approach to everything including top end stability lends to the completeness of this build


200+ps monster AZ-1 takes the stage


In 1992, Mazda’s “Autozam” brand put the world’s smallest supercar – the AZ-1 – on sale. This legendary machine mounted its Suzuki sourced F6A turbo engine in the middle and had gullwing doors, totally unlike any kei car before it.



Our focus this time is one such AZ-1; this one built specifically for high-speed cruising. Every aspect, from the chassis to the exterior and the interior has been customized. The engine is fully tuned too, in the most literal sense possible.



The F6A turbo engine has had it’s bore increased by 3mm, combined with 68φ pistons to increase displacement to 720cc. By adding a high-flow turbine, it achieves over 200ps at a maximum boost pressure of 1.4 kilograms. While the original 64ps was somewhat influenced by self-imposed controls, that’s *three times* the power output of the stock motor.



A dry shot of nitrous oxide provides an extra kick in the tail at higher speeds. It’s a reasonably moderate setting, only kicking in above 85% throttle, and even then only between 4000-7800rpm.



An F-CON V Pro stand-alone ECU takes care of engine management. All the stops are out here, with a custom pickup coil to extract ignition timing data and a direct ignition system that would usually find its home in a Silvia.



A 60φ full straight pipe dual exhaust leads to custom made titanium muffler exits on both sides.



No expenses are spared on the cooling system either, with a large radiator lurking under the front lid. An oil cooler has been added, too.



The interior has been completely refurbished. A large tachometer and boostmeter sit in the center of the dash. On the passenger side, extra 60φ meters relay additional information to the driver. On top of this, the seat backs have been altered to direct air from a duct towards the engine.



Zeal Function coilovers from Endless provide the foundation of the suspension setup, and to ensure a stable ride at high speeds, the stabilizers have been reinforced. The – rather striking – wheels are nostaligia inducing SSR Mark 1s.



As if in competition with the dramatic engine build, the exterior modifications are equally exhaustive. The one-off widebody kit smacks of attitude and takes performance into consideration too, including ducts that deliver air effectively to the engine bay.



Put this extensive list of modifications together, and the result is a 200km/h+ cruiser that will make you forget that it’s a kei car. Some might call it heresy to change the dynamics of a car this rare, but we have to admire the spirit of the owner who has built this car in his own image.